Synthesis of two new tripodal ligands and their cyclocondensation with 2-[2-(2-formylphenoxy)ethoxy]benzaldehyde in the presence of manganese(II) and cadmium(II) metal ions

Abstract

Two new asymmetric tripodal tetraamine ligands, 2-((bis(2-aminoethyl)amino)methyl)benzenamine (L 2) and 2-(((2-aminoethyl)(3-aminopropyl)amino)methyl)benzenamine (L 3) were synthesized and characterized. [1+1] Macrocyclic Schiff-base complexes containing 1,2-diphenoxyethane head units and a 2-aminobenzyl pendant arm, were synthesized as [MnL 4(MeOH)](ClO 4) 2 ( 1), [MnL 5(MeOH)](ClO 4) 2 ( 2), [CdL 4(H 2O)](NO 3) 2 ( 3) and [CdL 5(H 2O)](NO 3) 2 ( 4) from the metal ion templated cyclocondensation reactions of 2-[2-(2-formylphenoxy)ethoxy]benzaldehyde with the (L 2) or (L 3) tripodal tetraamine ligands. The crystal structure determination of ( 1) and ( 4) showed that the complex cations that had formed consisted of pentagonal bipyramidally coordinated Mn(II) and Cd(II) ions, centrally located in a N 3O 2 macrocycle, with one 2-aminobenzyl pendant arm. Supporting ab initio HF-MO calculations have been undertaken using the standard 3-21G ∗ and 6-31G ∗ basis sets.